This invention relates to communication systems, such as telephone systems, which utilize fiber optics for transmission and processing of communication signals.
Much effort has been expended in developing components and systems for utilizing the advantages of fiber optics in communication systems. It has been of particular interest to provide systems which can be interfaced into existing telephone systems without requiring replacement of equipment being used by users of the system. Thus, it is desirable that the system be readily interfaced with electrical as well as optical equipment.
Despite substantial progress in the development of optical systems, it has remained desirable to provide versatile, high-capacity, local-distribution communication systems which have a minimum of active components, (i.e. components that require supplemental power;) and which rely primarily on passive components for use off the customer premises. Moreover, whether or not the components be active or passive, it would be desirable to achieve such a system with a minimum amount of apparatus required at each subscriber (i.e. the user or customer) station. Such an achievement would not only minimize unauthorized access to communications but provide a means to reduce the total amount of equipment required by a system to the amount indicated by the statistical analysis of system usage.